JPS6077650A - Insulating varnish treating method and device therefor - Google Patents

Abstract

PURPOSE:To eliminate a cleaning and removing works of dropping liquid particles of insulating varnish by dipping an electric device which is preliminarily dried in an insulating varnish tank, removing the device from the tank at the prescribed velocity and then heating and drying it. CONSTITUTION:An electric device to be treated with insulating varnish 15 such as a stator 12 is preliminarily drived, and dipped in an insulating varnish tank 14 in which insulating varnish 15 having the prescribed viscosity is dipped. In this state, the stator 12 is removed from the tank 14 at the velocity obtained by the viscosity of the varnish 15, the surface tension on the liquid surface of the varnish 15 and its own weight of dropping liquid paticles. The removed stator 12 is heated and dried.

Description

[Detailed Description of the Invention] [Technical Field of the Invention] The present invention relates to a stator of an electrical device, for example, a rotating electric machine, in which a stator core with a winding wound thereon is immersed in an insulating varnish, and the stator is taken out and insulated. The present invention relates to an insulating varnish processing method and an apparatus for the same, in which varnish is dropped and the stator after the insulating varnish has been dropped is heated and cured.

[Technical background of the invention and its problems]

A first example of a conventional insulating varnish treatment method for the stator of a small electric device, such as an induction motor, includes the following steps. In the first step, as shown in Fig. 1, the insulated winding 11 is wound around the slots 10& of the stator core 10, and this is preheated to 60°C as shown in Fig. 5 to remove moisture from the stator. At the same time, the insulating varnish is easily impregnated into the insulating winding 11. In the second step, the stator plate preheated in the first step is placed in the insulating varnish tank 14 using the stator suspension fittings 13 as shown in FIG. It is immersed for several minutes in an insulating varnish 15 having a viscosity of 09 poise at a temperature of 45 degrees at a room temperature. This state is shown in FIG. In the third step, as shown in FIG. 3, the stator plate obtained in the second step is pulled up from the insulating varnish tank 14 by the stator hanging jigrow f1.9, and insulating varnish is dripped to remove unnecessary insulation. Try to remove as much of the varnish as possible, especially the insulating varnish from the inner peripheral surface of the stator core 1θ (the surface where the rotor is inserted). In the fourth step, the stator 12 obtained in the third step is heated in a dryer to polymerize and harden the insulating varnish impregnated into the insulating winding 11.

Although the insulating varnish treatment method for the stator U is completed through these steps, dripping droplets 15a of the insulating varnish 15 are generated on the inner circumferential surface of the stator core 10, as shown in FIG. This is because the insulating varnish is dripped in the third step, but this is simply caused by the weight of the insulating varnish drop.
Dripping liquid droplets 15& are generated on the lower half of the inner circumferential surface of the stator core 10. The occurrence of these dropped particles 15a can be prevented by lowering the viscosity of the insulating varnish 15. However, lowering the viscosity makes the insulating varnish thinner and less likely to adhere to the insulating winding. This will cause the insulation performance to deteriorate.
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For this reason, conventionally, the gap between the inner peripheral surface of the stator core 1θ and the outer peripheral surface of the rotor core (not shown) provided on this inner peripheral surface is, for example, 0.2 to 0.3. teeth,
Stator core 1 may come in contact with the rotor and interfere with rotation.
It became necessary to remove the dropped droplets 15a on the inner peripheral surface of θ with a file or the like. This work is troublesome and has the disadvantage of poor workability.

Therefore, an insulating varnish treatment method as described below has been conventionally used. This treatment method consists of 1. Instead of the third step described above, as shown in FIG. This is a process in which the cleaning rotary brush blade 7 is rotated to clean and remove dripping droplets 15a of the insulating varnish 15 on the inner circumferential surface of the stator core 10.

In this third step, the dripping liquid droplets 15 on the inner circumferential surface of the stator core 10
Although most of a is removed by washing, since the organic cleaning liquid is supplied to the inner circumferential surface of the stator core 10, there are the following drawbacks.

■ Workability decreases due to increased cleaning and removal work.

■ When cleaning the insulating varnish on the inner circumferential surface of the stator core 10, the insulating varnish adhering to the insulating winding 1, which is originally required, may be washed away, which may reduce the adhesion effect of the insulating varnish. At the same time, the thickness of the insulating varnish coating on the stator winding 11 decreases, leading to a decrease in insulation performance.

(2) Since the cleaning liquid mixes with the insulating varnish 15 in the tank 1-4, the viscosity of the insulating varnish decreases. If the viscosity of the insulating varnish decreases, it may not adhere to the stator windings, which is undesirable.

Therefore, it is necessary to correct the viscosity of the insulating varnish.

[Object of the invention]

SUMMARY OF THE INVENTION An object of the present invention is to provide an insulating varnish processing method that does not require cleaning and removal of dripping droplets of insulating varnish, and an insulating varnish processing apparatus for carrying out this processing method.

[Summary of the invention]

The method of the present invention involves pre-drying an electrical device to be treated with insulating varnish, immersing it in an insulating varnish bath containing an insulating varnish having a predetermined viscosity, and in this state, removing the electrical device from the varnish bath. is removed at a speed that is determined by the viscosity of the insulating varnish, the surface tension at the liquid level of the insulating varnish, and the weight of the dropped droplets, and the exposed electrical equipment is heated and dried. .

The device of the present invention has an insulating varnish that stores an insulating varnish inside, allows electrical equipment to be treated with the insulating varnish to be immersed and taken out, and has an overflow mechanism to keep the liquid level of the insulating varnish constant at all times. an immersion tank device; a temperature adjustment device capable of supplying insulating varnish into the immersion tank device and adjusting the temperature of the insulating varnish overflowing through an overflow mechanism of the immersion tank device; this temperature adjustment device and the insulating varnish; This is an insulating varnish processing device comprising a varnish dipping tank device and an insulating varnish circulation path formed so that the insulating varnish can circulate.

[Embodiments of the invention]

The present invention will be explained below with reference to the drawings, but first the method of the present invention will be explained. Here, the electric device will be explained using a stator of a rotating electric machine as an example, but the present invention is not limited to this. As the first step, the stator 12 with the stator windings 11 housed in the slots of the stator core 10 in FIG.
C1 in the figure) Higher temperature C2 For example 65 as in figure 9
℃. As a second step, an insulating varnish 15 having a viscosity of X2, for example, 1.6 poise as shown in FIG. 10, is placed in the tank 14 shown in FIG. In this way, the stator 1 is placed inside the insulating varnish 15.
When 2 is immersed, the temperature of the stator core is high, so the viscosity coefficient η2 of the deposited varnish is 0.7 poise, which is smaller than the viscosity coefficient ηl of the conventional deposit varnish, which is 0.9.19 poise. Become.

As a third step, the stator 12 immersed in the insulating varnish 15 is lifted up by lifting means (not shown) as shown in FIG. pull up at a speed of If the stator lift is pulled up at this speed, dripping droplets of insulating varnish will be less likely to occur.

This will be explained below with reference to FIG. Generally, the varnish viscous resistance f is f=cLητ (1). Here, C is the drag coefficient, t is the length of the stator core 15,
η is the viscosity, and τ is the moving speed of the stator core 15. (
Assuming that cL=constant in equation 1), the varnish viscous resistance f is proportional to the product of the viscosity η and the moving speed υ of the stator core 15. On the other hand, it holds true between the varnish liquid shear stress S and the viscosity η. Here, τ is the moving speed of the stator core 15, and y is the small part distance in the liquid (y in FIG. 11). Also, the descending speed of the insulating varnish drop (the moving speed of the stator core 15) τ2 is v2-1・k(gz+T)...
...(3) η2. In equation (3), g2 is the dead weight of 15 g of dropped droplets of the insulating varnish 15, T is the varnish liquid surface tension, and η2 is the viscosity of the insulating varnish 15. (3) Being in a relationship. Note that G is the resultant force of g2 and T.

Here, the surface tension T will be explained with reference to FIG. 11. Taking the X axis perpendicular to the Y axis, the power of the phrase Fl, F
2 comes into play. In this case, the force F1 is the force that causes the old edge varnish 15 to adhere to the surface of the stator core 100, and the force F2
is the force that tends to be absorbed by the liquid surface of the insulating varnish 15 in the tank. These forces are proportional to the area A of the microplane, and further proportional to the rate at which the moving speed τ of the stator core 10 changes with respect to X, that is, the speed gradient clx.

Fl=ηl A-・・・・・・・・・(4)x (4), In equation (5), η1 is stator core 100
This is the viscosity of the insulating varnish 15 that is about to adhere to the surface, which has a low viscosity due to the high temperature.

η2 is the liquid level of the insulating varnish 15 in the tank,
Since this is a low temperature, it has a high viscosity.In this way, η2>η1.'IJ'-et al., (4)
Comparing (5), F2 > Fl, and in the conventional method, the lowering speed of the insulating varnish v6 and the moving speed (pulling speed) of the stator core υ1 were higher than that of the insulating varnish.

As described above, in the method of the present invention, the temperature of the varnish adhering to the stator core 1o is increased by increasing the preheating and drying temperature of the stator I2, thereby reducing the viscosity of the insulating varnish and improving its fluidity. , in addition to increasing the descending speed of the insulating varnish 15, the dead weight g2 of the dropping droplets of the insulating varnish 15 is increased.
Since the stator core 10 is moved (raised) at a speed determined by the resultant force G of the liquid surface tension T and the liquid surface tension T, the dripping droplets 15a, which have been a problem in the conventional method, are hardly generated. Therefore, there is no need to wash and remove the dropped droplets 15a, it is possible to prevent the varnish adhering to the coil from flowing out due to the solution, and there is less need to correct the viscosity of the insulating varnish.

Next, an insulating varnish processing apparatus used to carry out the method of the present invention described above will be explained with reference to FIG. 12. The insulating varnish immersion tank device 20 includes an insulating varnish tank 23 having an inlet 21 and an outlet 22, and an overflow mechanism 24 provided inside the tank 23 on the outlet 22 side. This O-70-Mechanism 2
4 is, for example, a dam member provided vertically on the outlet 22 side in the tank 23. The temperature adjustment device 30 includes a cooling tank 31 that stores the insulating varnish from the outlet 22 of the tank 23, and a cooling coil 32 for cooling the insulating varnish in the cooling tank 31 to a predetermined temperature, for example. It is composed of a unit 33. The insulating varnish circulation path 40 connects the inlet 21 of the tank 23 and the cooling tank 31.
a first flexible pipe 41 that communicates with the tank 23; a pump 42 that is provided in the middle of the pipe 42 and is capable of controlling the flow rate for forcibly sending the insulating varnish 15 in the cooling tank 31 to the tank 23; The second flexible pipe communicates between the outlet 22 of the cooling tank 31 and the cooling tank 31. In addition to the above configuration, the tank 23 has a hanging rope 51 for vertically moving the insulating varnish dipping tank device 20, and a hydraulic cylinder 52 for lifting and lowering the hanging rope 51. It has a hydraulic pump unit 53 for driving the hydraulic pump unit 52. The stator hanging rope 13 is connected to the circulating conveyor 5
4, thereby making the stator 12 movable.

Hereinafter, the operation of the insulating varnish processing apparatus configured as described above will be explained. During varnish treatment, the pump 42 is driven, and the insulating varnish 15 in the cooling tank 15 is transferred to the dipping tank 2.
In the dipping tank 23, the insulating varnish 15 constantly overflows into the cooling tank 15 via the overflow mechanism 24. In this state, the stator U to be varnished is preheated to a predetermined temperature, the insulating varnish immersion tank device 20 is lifted by the hydraulic cylinder 52 from the dotted chain line position to the solid line position, and the stator U is placed in the immersion tank 23 as specified. After that, the hydraulic cylinder 52 lowers the immersion tank 23 from the solid line position to the two-dot chain line position at a predetermined speed, whereby the immersion tank 23
The stator 12 taken out from 3 is transferred to a circulating conveyor 54.
Send it to the drying process. In this case, it goes without saying that the insulating varnish 15 has a predetermined viscosity.

In this way, since the liquid level of the insulating varnish 15 in the immersion tank 23 is configured to be constant regardless of the size or number of stators, the liquid level of the insulating varnish 15 when the stator 12 is taken out is The relative speed of the stator 12 can be easily controlled to be constant. This is because the overflow mechanism 24 is provided, and if this is not provided, the rate of change in the liquid level of the insulating varnish and the speed at which the stator 1 is removed from the immersion tank 24 should be considered. It is troublesome because it has to be done. Furthermore, since the temperature of the insulating varnish 15 in the immersion tank 23 is cooled almost uniformly at the upper and lower parts, the temperature of the insulating varnish 15 does not become high only in the upper layer as in the conventional case. There is also little risk of hardening and deterioration. Furthermore, since the insulating varnish 15 in the immersion tank 23 is cooled, the solvent of the insulating varnish 15 hardly evaporates, improving the yield of the solvent and saving about 20 tons compared to the conventional method.

In addition, in the above-mentioned embodiment, the configuration for cooling the insulating varnish 15 was explained as the temperature adjustment device 3o, but the configuration is not limited to this, and depending on the time of use, the place of use, etc., the configuration may be configured to warm the insulating varnish to some extent. be.

[Effects of the invention]

As described above, according to the present invention, it is possible to provide an insulating varnish processing method that does not require cleaning and removal of dropped droplets of insulating varnish, and an insulating varnish processing apparatus for carrying out the method.

[Brief explanation of drawings]

Figures 1 to 4 are diagrams for explaining each step of the conventional insulation varnish treatment method, and Figure 5 is a temperature distribution diagram of the stator core, adhering varnish, and insulation varnish in the conventional insulation varnish treatment method. Figure 6 is a viscosity distribution diagram of insulation varnish and adhered varnish in the conventional insulation varnish treatment method;
8 and 8 are diagrams for explaining each process of the insulating varnish treatment method according to the present invention, and FIG. Figure 10 is a viscosity distribution diagram of the insulating varnish and the attached varnish in the insulating varnish treatment method of the present invention,
FIG. 11 is a diagram for explaining the effects of the present invention.
FIG. 2 is a diagram showing a schematic configuration of an insulating varnish processing apparatus according to the present invention. 10... Stator core, 11... Insulated winding, 1...
- Stator, 20... Insulating varnish immersion tank device, 21
... Inflow port, 22 ... Outflow port, 23 ... Immersion tank, 24 ... Overflow mechanism, 30 ... Temperature adjustment device, 31 ... Cooling tank, 32 ... Cooling pipe, 3
3... Cooler unit, 40... Insulating varnish circulation path, 41.43... Piping, No. 41...? Nzo. Applicant's Representative Patent Attorney Takehiko Suzue Figure 1 Figure 5 Figure 6 Figure 7 Figure 9 Figure 1゜Figure 11 Figure 7 To 1 Figure 12 E+ 30

Claims (2)

[Claims] (1) Preliminary drying of electrical equipment to be treated with insulating varnish;
This is immersed in an insulating varnish tank containing an insulating varnish with a predetermined viscosity, and in this state, the electrical equipment is removed from the varnish tank with the viscosity of the insulating varnish and the surface of the insulating varnish at the liquid level. A method for treating insulating varnish in which the removed electrical equipment is heated and dried by removing it at a speed that is compatible with the tension and the weight of the dropped droplets. (2) An insulating varnish immersion tank in which insulating varnish is stored, in which electrical equipment to be treated with the insulating varnish can be immersed and taken out, and which has an overflow mechanism to keep the level of the insulating varnish constant at all times. a temperature adjustment device capable of supplying insulating varnish into the immersion tank device and adjusting the temperature of the insulating varnish flowing through the overflow mechanism of the immersion tank device; An insulating varnish processing device comprising an insulating varnish circulation path formed between the device and the insulating varnish dipping tank device so that the insulating varnish can circulate.